Hey Camper6,
The high voltage machines I've posted are not Van de Graaffs, but are Wimshurst Machines.
They store their balanced charges in 2 capacitors which discharge through 2 spherical terminals when they can't hold any more charge.
The capacitors are the 2 cylindrical units coated inside and out with aluminum foil.
The Van de Graaff machine is actually a self-charging capacitor, with the upper terminal accumulating a charge on its inner surface, then discharging externally to a grounded object.
The large Van de Graaff shown was built by me, and had a yield of roughly 1,112,000 volts. I couldn't use it indoors because it would discharge through the ceiling to any neaby AC conduit and trip the house breakers, so I dismantled it, and the 30" sphere is now a garden ornament!
The smaller VDG is a commercial unit, with a yield of 250,000-300,000 volts, depending on humidity.
HiVoltageHal